By Ellalyn de Vera-Ruiz
LEGAZPI CITY (PNA) – The Philippine Institute of Volcanology and Seismology (Phivolcs) is considering lowering the alert level of Mayon volcano from 4 to 3 in the next few weeks if the volcano’s lower level of activity will continue.
Ed Laguerta, Phivolcs resident volcanologist in Bicol, said Monday that Mayon showed lower abnormal activity in the last 24 hours but thorough observation is still being done by scientists as there is no conclusive proof yet that the volcano’s restiveness is on a weakening stage.
He said Alert Level 4 is still up over Mayon and so is the 8-km extended danger buffer zone.
Laguerta is not discounting the possibility that Mayon may still produce an explosive hazardous eruption similar to the 1984 scenario where the volcano showed off a lull for one week before a strong and explosive explosion took place.
“We are closely studying the sudden change and decrease of S02 (Sulfur Dioxide gas emission) of Mayon which was decreased to 1,583 tons per day from the more than 3,000 tons of SO2 emission two days ago,” Laguerta said in a press briefing.
Phivolcs characterized Mayon Volcano’s activity in the past 24 hours as “sporadic to near continuous.”
Repeated lava fountains from 5:57 a.m. to 1:46 p.m. Monday and near continuous lava fountains from 3:59 p.m. Monday until Tuesday were observed.
These were accompanied by steam-laden ash plumes reaching 400 meters high and rumbling sounds heard up to 10 kilometers from the volcano.
Throughout Monday evening, lava flows and consequent incandescent rockfalls were observed in the Miisi and Bonga-Buyuan channels.
Mayon Volcano’s seismic monitoring network recorded a total of 116 volcanic earthquakes, most of which corresponded to lava fountaining events.
Sulfur dioxide emission remains at an average of 1,583 tons per day since Feb. 2.
However, Phivolcs pointed out that the there is still a sustained swelling or inflation of the landform since October and November 2017, consistent with pressurization by magmatic intrusion.
Phivolcs continues to advise the public to be vigilant and desist from entering the eight-kilometer-radius danger zone.
